Coaxial cable splicer



April 25, 1961 G. E. METCALF, JR

COAXIAL CABLE SPLICER Original Filed March 28, 1958 2 Sheets-Sheet 1INVENTOR. GUY E. METCALF, JR. WW

ATTORNEY Y W 7?- Wm AGENT i -Qa Aprll 25, 1961 G. E. METCALF, JR2,981,649

COAXIAL CABLE SPLICER Original Filed March 28, 1958 2 Sheets-Sheet 2 ETOR.

2 INV N 33 GUY E. METCA F, JR.

BY WW...

ATTORNEY I AGENT United States Patent COAXIAL CABLE SPLICER Guy E.Metcali, Jr., Cedar Vale, Kans. (193311 AACS Sq., APO 864, New York,N.Y.)

Original application Mar. 28, 1958, Ser. No. 724,789. Divided and thisapplication July 27, 1959, Ser. No. 829,940

g 4 Claims. (Cl. 154-432) (Granted under Title 35, US. Code (1952), see.266) individual lengths of coaxial cable, andthis application forLetters Patent is a division of my copending application Serial No.724,780, filed on March 28, 1958, now Patent No. 2,923,806.

In the utilization of coaxial cable for remoting video information, anumber of one-thousand foot cable lengths connected together arerequired. The usual connectors on each end of these cable lengths do notprovide a watertight connection, resulting in a poor signal to noiseratio as well as an excessive amount of alternating current hum on thevideo signals supplied to the remote indicator. Moreover, it wasnormally found to be practically impossible to dry out collection ofmoisture in the coaxial cable braid between the outer jacket and thedielectric. The latter resulted in a shorting-out of the wet cableconnections effecting an unreliable video signal received at the remotesite, as for example, in radar ap proach controls and ground-controlledapproach (GCA) aircraft landings. The coaxial cable splicer of thepresent invention has been developed in order to eliminate the abovedescribed problems.

It is an object of the present invention, therefore, to provide a uniquemeans of connecting individual lengths of coaxial cable.

it is a further object of the invention to provide a novel cable splicerdevice for waterproofingv the connection between individual lengths ofcoaxial cable.

A still further object of the invention is to utilize a device forjoining cable lengths together through the application of constantpressure and heat.

Another object of the invention resides in a mechanism for joining cablelengths by the application thereto of external material.

A still further object of the invention is in a system for joining theends of cable lengths through constant pressure controlled by a constantweight acting through a piston.

An additional object of the invention resides in a cable splicer devicethat eliminates the shorting out of wet cable connections atinappropriate moments making for an inoperative signal received at aremote site.

Other objects and advantages of the invention will become apparent fromthe following description taken in connection with the accompanyingdrawings, in which like reference characters refer to like parts in theseveral figures. I

Fig. 1 is an isometric view of the cable splicer of the presentinvention, illustrating the splicing and molding sections in assembledcondition.

Fig. 1a is a bottom perspective view of the heater assembly unitutilized with the inventive cable splicer of 2,981,649 Patented Apr. 25,1961 Fig. 1, illustrating additional details of the combination heaterand upper mold assembly.

Fig. 2 is a top view of the cable splicer of Fig. 1, illustratingadditional details of the splicing and molding sections with the cablelengths to be spliced and molded in mounted condition.

Fig. 2a is an enlarged somewhat top perspective view of the moldingsection of the cable splicer of Fig. 1.

Fig. 3 is a cross-sectional view taken about on line 3 3 of Fig. 2 ofthe cable mold bracket assembly illustrating additional details of thecable mold clamps and bracket utilized with the present invention.

Figs. 4, 4a, 4b and 4c, respectively, are schematic, partly broken awayviews representing the various conditions of the cable utilized with thecable splicer of the present invention after the molding thereof hasbeen accomplished.

Fig. 5 is a schematic view of the wiring diagram that may be utilizedwith the cable splicer of the instant inven tion in order to perform thenecessary splicing and molding operations.

Before the initial cable splicing operation is accomplished, the cablesections to be spliced must be appropriately prepared in various stagesbefore being mounted L in the cable splicer of the invention. After aselected pair of cable sections are prepared in the manner described indetail in my copending. application Serial No. 724,780, filed March 28,1958, both of said cable sections are then mounted in the cable splicerassembly and spliced in the manner described in the aforesaid copendingapplication.

With particular reference to Figs. 1 and 2 of the drawings, the cablesplicer assembly of the present invention preferably includes analuminum case :1 having a Bakelite or other hard plastic top cover '2and an aluminum bottom cover plate 3. Positioned on the top cover plate1 is the rod-mounting bracket 4, right and left-hand splicer clamps 55,56, brass rods 27a and 27b and microswitch 12 utilized for accomplishingthe splicing of two cable sections in the manner previously described indetailin copending patent application Serial No. 724,780, filed March28, 1958. 7

Referring again to Fig. l and also to Figs. 2 and 2a of the drawings,the coaxial cable mold bracket of the present invention is indicated at5 as mounted on the top cover plate 2 on the opposite side thereof fromthe previous mentioned mounting bracket 4 as by means of the screws 25.Said mold bracket 5 may consist of a one-eighth A3) inch flat steelplate having one edge thereof formed with a pair of spaced uprightsupports 50 adjacent each end thereof for supporting a lower steel orbrass cable mold end clamp 44 thereon which lower mold end clamp 44 issilver soldered to said upright supports 5a. in addition, a lower coppercable center mold 20 is silver soldered on an additional pair of spacedupright supports 5b formed on the edge of said mold bracket 5 halfwaybetween upright end supports 5a. Each of said lower mold end clamps 44is provided with a cable mold clamp yoke assembly 16. As seen clearly inFigs. 1 and 3 of the drawings, said clamp yoke assembly 16 consists ofan upper cable mold end clamp 43 comple mentally disposed relative tosaid lower cable mold clamps 44, a cable mold end clamp yoke 42 silversoldered to said upper cable mold end clamp 43 and a screw 18 and wingnut 19 for retaining or locking said clamp yoke 42 and upper cable moldend clamp 43 soldered thereto in position and clamping the respectiveends of the cable lengths 57 to be spliced. As seen clearly in Figs. 2aand 3 of the drawings, coaxial cable mold bracket 5 incorporates aprojecting slotted surface indicated generally at Sr: and extendingbetween each respective pair of upright supports 5a and 5b. Each cablemold end clamp yoke 42 tapers downwardly into a portion 42a (note Fig.3) terminating in a narrowed bottom portion 42b extending at rightangles thereto into the open space between respective upright supports5a. Each screw 18 is affixed at one end as by silver soldering to saidnarrowed bottom portion 42b and extends through a respective slot of theslotted surface 5c at its other end where it is engaged with wing nut 19for appropriate adjustment and clamping. A similar projecting slottedsurface 5d extends between the upright supports 5b of the lower cablecenter mold 20 with an identical screw and nut 18, 19 for mounting thecenter cable mold clamp yoke 17. Said cable mold clamp yoke '17 is seenclearly in Figs. 1 and 3 of the drawings and incorporates a pair ofspaced projecting somewhat arcuate fingers 17a on the upper end thereofwhich fingers 17a are adapted for engagement with the upper center mold20a which upper center mold 200 is silver soldered to the combinationheater and upper mold assembly unit 15. Said combination heater andupper mold assembly unit consists of a heater assembly 15a incorporatinga heater cartridge 33, and an upper mold assembly 15b consisting of acylinder'15c,- piston rod 14 for insertion at its lower end into saidcylinder 15c, and a weight 13 which may consist of a tin can filled withlead mounted on the upper end of piston rod 14 for purposes to behereinafter explained in detail. In addition, an electrical cord 51 isattached at one end to the heater cartridge 33 of heater assembly 15aand extends to an opening (note Fig.1) in top cover plate 1 forconnection in circuit with transformer 38, as shown in Fig. 5 of thedrawings. Moreover, a push button switch 28 and a toggle switch 29 aremounted on top cover plate 2 (Fig. l) and are utilized, respectively, toenergize the welding circuit as set forth in the aforesaid parentcopending application Serial No. 724,780 and the heater assembly unit(note Fig. 5).

After the two cable ends to be spliced have been prepared, the centerconductors 61 thereof are than mounted and welded in the cable splicerassembly as previously noted with reference to the aforesaid copendingapplication Serial No. 724,780. After welding is completed, the wiresare removed from the fixed and movable clamps 55, 56 (Fig. 2) and thewelded area is scraped lightly with a knife. At this time, the wirebraid 59a that has been previously fanned out is checked to ensure thatit is still perpendicular to the cable 57. Next, the spliced cable 57 isplaced in the molding section of the inventive splicer with the exposedcenter conductor 61 in the center cable mold and adjacent end portions58 in oppositely disposed lower cable mold end clamps 44. One uppercable mold end clamp 43 and the cable mold clamp yoke 42 solderedthereto is complementally engaged over the top of one end portion 58 ofthe spliced cable and tightened securely in place. The oppositelydisposed uppercable mold end clamp 43 and cable mold clamp yoke 42 isloosely complemental'ly engaged over the top of the other end portion 58of the spliced cable and this end of said cable pulled with a pressureof approximately pounds to ensure proper centering of the exposed centerconductor 61 in the lower center cable mold 20 at which point, uppercable mold end clamp 43 and cable mold clamp yoke 42 on the latter endare securely tightened in place. It is noted that it is most importantthat correct centering of the exposed wire or center conductor 61 beensured, since any deviation of the conductor from the correct centerposition changes the characteristic impedance at that point and resultsin reflections of the primary signals on the line and degeneration ofthe display on the remote indicator. After the spliced wire or centerconductor 61 has been correctly fastened in the molding section asdescribed above, the upper cable center mold 20a of the combinationheater and upper mold assembly unit 15 is placed over said exposed wireof center conductor 61 in the lower center cable mold 20 and securelyfastened in place by means of the center mold clamp yoke 17. The uppermold assembly indicated at 15b in Fig. 1 consists of a cylinder 15ccontaining a supply of prepared polyethylene that extends approximatelyone half inch below the top of said cylinder 15c. Piston rod 14 isinserted into cylinder 15c and applies continuous pressure on theprepared polyethylene therein by means of the weight 13. Thereafter,when heater toggle switch 29 is actuated to energize heater assembly 15aand thereby heat the cylinder 150, the prepared polyethylene materialtherein is forced out through the extrusion hole 15d (note Fig. la) intothe lower cable center mold 20 to cover the center conductor 61. Theweighted upper mold assembly 15b is not removed until a slight amount ofpolyethylene has extruded out both ends of said cable center mold 20 andallowed to cool. It is noted that it is necessary to cut off the heaterswitch 29 after a few seconds only if the molding operation is startedat room temperature. If cooler temperatures prevail, however, switch 29is left on for a longer period. After the extruded polyethylene materialhas cooled, the weighted piston rod 14 is removed from the cylinder 15cby twisting the weight 13 in a circular motion and pulling upwardly. Thecombined heater and upper mold assembly unit 15 and cable mold endclamps 43 and yokes 42 are removed. The cable 57 is then removed fromthe mold section and the spliced section, center condoctor 61, examinedfor air bubbles, poor seal or misalignment of the center conductor and,if so, the entire spliced area is cut out and the above describedprocedure is repeated.

Referring particularly to Figs. 4, 4a, 4b and 4c of the drawings, aspliced cable is shown generally at 57 and consists of two cablesections each having an outer cable jacket 58, an exposed cable shield59 with a fanned section 59a, a polyethylene dielectric 60 and a centerconductor 61, the latter having been molded together as a single unit inthe manner previous described. In addition, excess polyethylene materialindicated at 61a has been formed on the surface of dielectric 60 duringthe molding process described above. This excess is neatly trimmed 01fby a sharp knife. Next, one of the loose cable shields 59 is slid backin its proper position over exposed dielectric 60. Said cable shield 59,which should be as snug as possible against dielectric 60 with fannedout section 59a still braided, is held in place by wrapping withapproximately twenty turns of No. 30 wire indicated at 62 in Fig. 6a onthe drawings. The other loose cable shield 59 is likewise slid back intoits proper position over the remaining portion of exposed dielectric 61in overlapping and tight relation to said first cable shield and thensecurely fastened with approximately twenty turns of No. 30 wire as seenat 62 in Fig. 6b. A slight amount of soldering paste is applied to theoverlapped portion of said shields. Finally, after preheating asubstantial amount of solder is applied'to the overlapped portions ofcable shield 59 with said overlapped portions being twirled veryrapidly. Precaution should be taken not to attempt a perfect solderconnection on the entire overlapped portions since excessive heat willmelt the polyethylene and thus destroy the impedance characteristics ofcable 57. The spliced area of cable 57 is then wrapped with a one-thirdoverlap layer of vinyl tape with the tape overlapping outer cable jacket58 one inch on each end as illustrated at 63 in Fig. 4c of the drawings.This taped area is then dipped in liquid vinyl, allowed to dry for atleast one hour, and then redipped. It is noted that should the liquidvinyl thicken because of exposure to air, it may be thinned with anyappropriate paint thinner.

Thus, a new and unique cable splicing and molding device has beendeveloped by the present invention wherein the previously spliced centerconductor ends of two preselected cable sections are inserted in a moldsection and molding material applied thereto.

I claim: v

1. In a. cable splicer machine for splicing cable seetions comprising anouter case having a top cover insulated plate, a bottom cover plate anda power transformer positioned within said outer case in dependingmounted condition relative to the inside of said cover plate, a cablemold bracket mounted on said top cover plate, said cable mold brackethaving a pair of upright lower mold end clamps adapted to receive theopposite ends of previously welded cable sections and a lower centermold adapted to loosely receive the welded area of said cable sections,each of said lower mold end clamps having a cable mold clamp yokeassembly adapted to clamp said opposite ends of said cable sections ineach of said lower mold end clamps, and a combination upper mold andheater assembly unit in complemental engagement with said lower centermold retaining therein the welded area of said cable sections, saidupper mold and heater assembly unit comprising an upper mold assemblyconsisting of a relatively elongated cylinder open at the bottom endthereof and adapted to contain a supply of polyethylene material andincorporating an upper center i mold integrally formed in transverserelation with the bottom end of said cylinder and in complementalengagement with said lower center mold and having a relatively smallbottom extrusion hole communicating with the interior of said cylinder,a heater assembly integrally aflixed adjacent said cylinder andcontaining a heater cartridge in circuit with said power transformeradapted to heat said supply of polyethylene within said cylinder, and aslidably mounted, relatively elongated weighted piston closing the upperend of and positioned within said cylinder applying continuous pressureon said supply of polyethylene material forcing said polyethylenematerial through said relatively small bottom extrusion hole outwardlyin opposite directionsthroughout said lower center mold to coat thewelded area of said cable sections therewith on energization of saidheater cartridge by said transformer.

2. In a cable splicer device for splicing the exposed ends of a pair ofcables, means for molding the spliced ends of said cable comprising alower cable mold unit having a pair of spaced oppositely disposed andlongitudinally aligned, lower cable mold end clamps for receiving theunexposed end portions of said cables and a center cable moldintermediately disposed between said pair of lower cable mold end clampsfor receiving the exposed spliced ends of said cables disposed inwardlyof said end portions, means for securely fastening said spliced cableends within said lower cable mold comprising an upper mold unit incomplemental engagement with said lower cable mold and means forretaining said upper mold unit in complemental engagement with saidlower cable mold comprising a cable mold clamp yoke having a pair ofspaced projecting fingers on the upper end thereof in engagement withsaid upper mold unit, and a combination heater and upper mold assemblyincluding an upright cylinder integrally formed with said upper moldunit and incorporating a supply of plastic material integrally formedadjacent to said heater assembly as a single unit, said cylinder havinga weighted piston rod for insertion therein in continual contact withthe upper surface of said plastic material and closing the upper end ofsaid cylinder, said upper mold unit having an extrusion opening in thebottom surface thereof in communication between the interior of saidcylinder and said lower cable mold unit for receiving said plasticmaterial under action of said weighted piston rod and depositing thesame in said lower cable mold unit outwardly in opposite directions overthe exposed spliced ends of said cables.

3. In a cable splicer device for splicing the exposed ends of a pair ofcables as in claim 2, said lower cable mold unit comprising a coaxialmold bracket consisting of a flat plate having one edge thereofincluding a first and a second pair of'spaced upright elements formedadjacent opposite sides thereof, each supporting one end of a lowermetallic mold end clamp integrally formed therewith, a third pair ofspaced upright elements formed along one edge of said mold bracketintermediate said first and second spaced upright elements, a lowercable center mold integrally formed on said third pair of spaced uprightelements and extending in alignment with said pair of lower cable moldend clamps and a cable mold clamp yoke assembly provided for each of apair of lower mold end clamps and each consisting of an upper cable moldend clamp complementally disposed relative to said lower mold end clampand a cable mold end clamp integrally formed relative to said uppercable mold end clamp, and adjustable locking means for positivelylooking said clamps relative to said coaxial mold bracket and therespective ends of said spliced cable comprising a cable mold end clampyoke for each of said clamps, each of said cable mold end clamp yokeshaving a portion tapering downwardly and terminating in a narrowedbottom portion extending transverse thereto into the space between arespective pair of said spaced upright elements and adjustablypositioned locking means rigid-1y attached at one end to said narrowedbottom portion and means releasably holding the other end thereof tosaid bracket.

4. In a splicer device for splicing the exposed ends of a pair ofcables, means for molding and waterproofing the spliced ends of saidcables comprising a coaxial cable mold bracket having a pair ofprojecting slotted end surfaces extending outward-1y from and along oneedge thereof on opposite sides of said bracket and a projecting slottedcentral surface extending outwardly of said one edge intermediate of,and parallel to, said pair of slotted end surfaces, a pair of spacedupright end supports extending transverse to said slotted surfaces oneach side of said central projecting surface, a relatively elongated,lower cable mold end clamp silver soldered on each of said pair ofupright end supports supporting opposite ends of said pair of splicedcables and a relatively short, lower cable center mold silver solderedon said pair of upright central supports in longitudinal alignment withsaid pair of end supports and supporting the exposed ends of said pairof spliced cables in cradled relation therein, an upper cable mold endclamp yoke mounted on and integrally formed with each of said cable moldend clamps, each of said lower cable mold end clamps incorporating meansfor clamping said upper end clamp yokes and the upper cable mold endclamps integrally formed therewith in complemental, engaging position onsaid lower end clamps comprising a lower portion tapered downwardly intoa bottom, narrowed yoke portion extending downwardly between said spacedupright end supports on each end of said cable mold bracket to a portionextending at right angles thereto into the open space between said pairof spaced upright end supports and parallel to said pair of projectingslotted end surfaces, an elongated clamp screw aflixed at one endthereof to each of said bottom, narrowed yoke portions and extendingdownwardly at the other end thereof through said projecting slotted endsurfaces into clamping engagement with a wing nut, and a combinationheater and upper mold assembly unit comprising a heater assemblyelectrically interconnected with and under control of a powertransformer and a main heater switch and an upper mold assemblyincluding a main housing mounted adjacent to and in continuous contactwith said heater assembly and containing a supply of plastic ma terial,an upper cable center mold integrally afiixed to said main supplyhousing in transverse relation thereto in complemental clampingengagement with said lower cable center mold and having a relativelyreduced extrusion opening incorporated in the bottom surface thereof andin communication with the interior of said integrally formed main supplyhousing and a weighted 7 plunger rod slidably engaged within said mainsupply subsequently to heating and liquefying said plastic mahousing incontact with the plastic material contained terial by means of saidheater assembly. 6.111 a l p c9ntmuus pressure Q P forcmg saldReferences Cited in the file of this patent plastlc matenal m a downwarddlreotlon outwardly 7 through said communicating extrusion opening intosaid 5 t V UNITED STATES PATENTS lower cable center mold and insurrounding, adhering re- 1,583,815 Trebes May 11, 1926 lation to theexposed ends of said pair of spliced cables 2,312,652 Komives et a1.Mar. 2, 1943

2. IN A CABLE SPLICER DEVICE FOR SPLICING THE EXPOSEDD ENDS OF A PAIR OFCABLES, MEANS FOR MOLDING THE SPLICED ENDS OF SAID CABLE COMPRISING ALOWER CABLE MOLD UNIT HAVING A PAIR OF SPACED OPPOSITELY DISPOSED ANDLONGITUDINALLY ALIGNED, LOWER CABLE MOLD ENDS CLAMPS FOR RECEIVING THEUNEXPOSED END PORTIONS OF SAID CABLES AND A CENTER CABLE MOLDINTERMEDIATELY DISPOSED BETWEEN SAID PAIR OF LOWER CABLE MOLD END CLAMPSFOR RECEIVING THE EXPOSED SPLICED ENDS OF SAID CABLES DISPOSED INWARDLYOF SAID END PORTIONS, MEANS FOR SECURELY FASTENING SAID SPLICED CABLEENDS WITHIN SAID LOWER CABLE MOLD COMPRISING AN UPPER MOLD UNIT INCOMPLEMENTAL ENGAGEMENT WITH SAID LOWER CABLE MOLD AND MEANS FORRETAINING SAID UPPER MOLD UNIT IN COMPLEMENTAL ENGAGEMENT WITH SAIDLOWER CABLE MOLD COMPRISING A CABLE MOLD CLAMP YOKE HAVING A PAIR OFSPACED PROJECTTIN FINGERS ON THE UPPER